Project Summary/Abstract The International Workshop on Retroviral Pathogenesis, now in its 31st year, has long served as a forum for the exchange of new research findings and concepts on all aspects of retroviral pathogenesis from molecular mechanisms to the immunological parameters of host-virus interaction. The conference will continue a tradition of intimate, engaged scientific interaction on all aspects of retroviral pathogenesis with strong emphasis on animal retroviruses as models for human disease. Retroviral pathogens of humans and animals in all retroviral genera are the subject of scientific presentation and vibrant discussion. Topics at the workshop will include retrovirus entry and integration, replication and restriction, assembly, immune responses, oncogenesis, pathogenesis, new and emerging pathogens, endogenous retroviruses, and animal models of disease. Approximately 100 participants are anticipated, including principal investigators, postdoctoral trainees and graduate students. Planned for October 13-16, 2019 in Padova, Italy, the small size and format of the conference supports concentrated interaction and deep scientific engagement. The conference fosters the professional development of junior investigators by affording them the opportunity to present their current work to a panel of engaged colleagues and to serve as Session Chairs. The overarching goal of the conference is to provide a forum that fosters continued scientific engagement leading to innovative conceptual advances and research in the area of retroviral pathogenesis, broadly defined. The conference will address this goal through three specific aims: (1) Bring together national and international scientific leaders in the field, together with junior investigators, postdoctoral and student trainees; (2) Provide opportunities for five invited keynote scientific presentations and discussions as a group, interspersed with more intimate opportunity for discussion and interaction; (3) Provide platform opportunities for junior investigators, women and underrepresented minority scholars through scientific presentation and/or designation as Session Chairs; and (4) Provide Writing Workshop covering topics such as how to frame your research for publication, the steps a manuscript goes through in the editorial process, the mechanics of writing and research and publication ethics.